This application claims the priority of German application No. 19709416.3-13, filed Mar. 7, 1997, the disclosure of which is expressly incorporated by reference herein.
This invention concerns a particularly constructed device for robotizable refuelling of a vehicle.
A device of this type is known from German patent publication DE 195 32 774 C1. The refuelling arrangement described in this publication includes a docking element which has a basically circular central recess for accommodating a pistol nozzle. The docking element has a peripheral inner gearing into which an outer gearing on the pistol nozzle engages while docking. The docking element and the pistol nozzle form two docking partners which are locked in a peripheral direction. For locking in an axial direction, at least one locking element is installed on the pistol nozzle which engages in an annular space below the inner gearing in the docking position. The docking element includes two annular elements which are arranged upon each other. The lower annular element is fastened on the filling tube of the motor vehicle tank and the upper annular element is pivoted on the lower annular element. An attachment of the lower annular element is created in a bayonet lock on the retracted edge of the filling tube. For this purpose, a hollow cylindrical ring carrier element provided with a central passage is fastened by a clip connection which supports a locking ring provided with radially projecting bayonet arms.
A compression spring is braced between a connection formed on the free end of the ring carrier element and the bayonet arms of the locking ring. The locking ring is held rotation-proof within certain limits owing to the load of the compression spring, but nonetheless remains axially movable. For fastening the docking element, the ring carrier element is inserted into the filling tube. The bayonet arms of the locking ring are passed through appropriate recesses in the recessed edge of the filling tube.
After installation of the lower annular element on the filling tube, the docking element is rotated in a peripheral direction, after which the bayonet arms are led along a ramp-like groove on the underside of the edge of the filling tube running in a peripheral direction and connecting with the recesses in a peripheral direction up to a catch. The bayonet arms are then clamped in the groove in the form of a bayonet lock. Upon docking, the robot nevertheless executes certain rotations relative to the vehicle, for example, on the part of the robot. These rotations are performed in order to lock or unlock the pistol nozzle in the docking element, or in order to swing the lid held on the docking element horizontally. Rotations likewise occur when the vehicle is shifted into the docking position when the vehicle occupants get in or out. These rotary motions can lead to the docking element, together with the docked pistol nozzle, being twisted against the locking direction of the bayonet locking so that a loose locking or, at worst, an unlocking of the docking element at the filling tube occurs. The tank filling is thus interrupted in a most undesirable manner. Attaching the docking element inseparably to the filling tube during vehicle assembly to eliminate this defect is conceivable. The docking element, however, should be capable of being retrofitted in used vehicles. Additionally, refuelling at usual dispensing pumps must continue to be possible. Consequently, the docking element must remain capable of being dismounted in connection with the latter, as simply as possible, and with a reasonable expenditure of energy.
It is a primary object of this invention to refine a device representative of this type such that safe filling of a vehicle fuel tank is made possible in a secure manner.
This object is accomplished by providing a particular device for robotizable refuelling of a vehicle. The device includes a docking element which can be installed on a filling tube of a vehicle fuel tank for accommodating a pistol nozzle, in which the piston nozzle can be locked in an axial and peripheral direction, and which has a central passage opening for a fill pipe of the piston nozzle. A hollow, cylindrical ring carrier element is fastened underneath the docking element and provided with a central passage. A locking ring is held, without torsional movement but axially movable, on the carrier element. A compression spring is braced between an underside of the locking ring and a connection of the ring carrier element. Radially projecting bayonet arms are provided on the locking ring by which the device can be installed on an inlet edge of the filling tube. The edge of the filling tube is provided with recesses for guiding the bayonet arms through to provide a bayonet closure.
A coupling ring borne by the ring carrier element is arranged torsion fast (against rotation) on the upper side of the locking ring. Catch elements, constructed so as to correspond to each other, are defined on an upper side of the coupling ring and on an underside on the docking element. The docking element can be engaged by these catch elements with the coupling ring.
The invention assures safe refuelling in a simple manner by providing a coupling ring between the underside of the docking element and the locking ring. Although the coupling ring is inherently capable of rotation, it is arranged to rotate with the filling tube in the fitting position of the docking element. The docking element is subsequently fixed on the coupling ring by rotating the docking element in relation to the coupling ring. The docking element is secured in the peripheral direction in this way. owing to this torsion-proof arrangement of the coupling ring and the torsion-proof arrangement of the docking element peripherally (likewise attained by fixing the docking element in the coupling ring), a rigid connection of the docking element with the filling tube is brought about in a peripheral direction. The rigid connection can be released when needed since the fixation of the docking element can be eliminated by manual, axially directed traction. Consequently, the torque acting on the docking element is absorbed without being transmitted to the locking ring for a possible unlocking of the docking element.